Challenges to Evidence Based Medicine – the need for more and better research. S Arulkumaran Professor Emeritus in O&G St George ’ s University of London. “ A Fresh Look at ” Interpreting Evidence. RCTs & Meta Analysis Case control studies Prospective descriptive studies
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Challenges to Evidence Based Medicine – the need for more and better research
Professor Emeritus in O&G
St George’s University of London
“A Fresh Look at”Interpreting Evidence
Planned caesarean section for term breech deliveryG Justus Hofmeyr1,*, Mary Hannah2, Theresa A Lawrie3Editorial Group: Cochrane Pregnancy and Childbirth Group Published Online: 22 APR 2003Assessed as up-to-date: 2 AUG 2011
HYPERTENSIVE DISEASE IN PREGNANCY
AND THE USE OF LABETALOL
There is one small head-to-head RCT comparison of oral labetalol vs parenteral hydralazine (Walker JJ et al. Postgrad Med 1983) - underpowered to draw any conclusions.
On the basis of this trial, however, considerable experience has been gained in Yorkshire as part of their successful guideline (Tuffnell DJ. BJOG 2005)
Upon that success - recommendation was made in the 2011 NICE guidelines that oral labetalol be the drug of choice.
It was listed as the agent of first choice. The onset of action of oral labetalol is 20-120 minutes, which about the same as methyldopa and intermediate-acting nifedipine
Peter von Dadelszen
Other than the published pharmacodynamics (e.g., drug monographs), the most supportive methyldopa data come from Hamilton M & Kopelman H. BMJ 1963, which show that the time to effect in patients receiving methyldopa and diuretic together i.e. similar to women with pre-eclampsia who are volume constricted.
Currently, in PRE-EMPT Trial - Nifedipine, labetalol and methyldopa are tested in a RCT of women with severe pregnancy hypertension.
The trial is led by Hillary Bracken from Gynuity and recruiting in Nagpur, India.
Bacterial vaginosis as a risk factor for preterm
delivery: a meta-analysis.
Leitich et al.Am. J. Obstet. Gynecol. 2003; 189:139-147.
The earlier the diagnosis of BV the greater
the risk of adverse outcome
Antibiotic treatment of BV in pregnancy: a meta – analysis
Leitich et al. Am J Obstet Gynecol 2003;188:752 - 758
Treatment initiated early made significant difference,
treatments initiated >20wks made no difference.
Systematic review of antibiotic for the treatment of bacterial vaginosis in pregnancy comparing preterm delivery rates (< 37 weeks) with any antibiotic versus placebo or no treatment. Adapted from McDonald et al 2005
Cochrane review of all
trials showing lack of
evidence to support
Effect of antibiotics therapy vs placebo for intermediate flora or bacterial vaginosis on the risk of preterm birth:
Adapted from McDonald et al
Early Rx using oral clindamycin - significant reduction
Effect of antibiotics therapy vs placebo for intermediate
flora or bacterial vaginosis on the risk of preterm birth:
Ugwumadu et al 2006 (unpublished)
Unpublished meta-analysis of all RCTs using
early oral clindamycin showing benefit
The gestation at diagnosis and
Treatment influences the outcome
Is there evidence to do EFM in high risk labour?
Is there evidence to do EFM in low risk labour?
Does CTG reduce intrapartum mortality?
Retrospective studies Historical Controls – 1970s
Intrapartum Fetal Heart Rate monitoring Vs Intermittent Auscultation
Vintzelios et.al. Obstet Gynecol 1995
Haverkamp et.al. Am JO&G 1976 & 1979; Renou et.al. Am J O&G 1976; Kelso et.al. Am J Obstet Gynecol 1978; Wood et.al. Am J Obstet Gynecol 1981; Mac Donald et.al. Am J O&G 1985; Neldam et.al. Eur J Obstet Gynecol1986; Luthy et.al. Obstet Gynecol. 1987; Vintzileos et.al. Obstet Gynecol. 1993
Comparing continuous electronic fetal monitoring in labour (cardiotocography, CTG) with intermittent listening (intermittent auscultation, IA)
Alfirevic Z, Devane D, Gyte GML; Published Online: November 8, 2013
Review included 13 trials involving over 37,000 women that compared continuous CTG monitoring with intermittent auscultation (listening). Most studies were not of high quality and the review is dominated by one large, well-conducted trial of almost 13,000 women who received one-to-one care throughout labour. In this trial, the membranes were ruptured artificially (amniotomy) as early as possible and oxytocin stimulation of contractions was used in about a quarter of the women.
Overall, there was no difference in the number of babies who died during or shortly after labour (about one in 300).
Fits (neonatal seizures) in babies were rare (about one in 500 births), but they occurred significantly less often when continuous CTG was used to monitor the fetal heart rate.
There was no difference in the incidence of cerebral palsy, however, other possible long-term effects have not been fully assessed and need further study.
Continuous monitoring was associated with a significant increase in CS & IVD. Both procedures are known to carry the risks for mothers although the specific adverse outcomes were not assessed in the included studies.
Incidence of IP still births & NN deaths
Mongelli et al, BJOG 1997
Mongelli et al, BJOG 1997
What % of women were electronically monitored in the EFM group?
What % CTG were not interpretable in the first stage? In the second stage?
Did it increase CS or IVD rate?
Did the women in the IA group have FBS in labour?
What was the commonest indication for FBS?
I) Abn CTG of FHR?
iii) Labour> 8 hrs?
FETAL SCALP BLOOD SAMPLING
EFM is equivalent to EFM if FBS is performed for women in
labour > 8 hrs ???
Entry Criteria – at ARM must have clear amniotic fluid
What was the mean cervical dilatation at ARM?
Did it increase CS or IVD?
AT is of little value if ARM at < 1.5 cm shows clear fluid
Effect of partogram use on outcomes for women in spontaneous labour at term
Lavender T, Hart A, Smyth RMD; Published Online: July 10, 2013
It has been unclear whether a partogram should be used and, if so, which design of partogram is better for women and babies.
Review authors identified six randomised controlled trials involving 7706 women in spontaneous labour at term. Two studies, with 1590 women, assessed introducing the use of a partogram versus routine care without a partogram. Four studies, involving 6116 women, compared different types of partograms.
Overall, there was no evidence from this review that using a partogram reduced or increased CS rates or had any effect on other aspects of care in labour.
Where different types of partogram were compared, no design appeared better than others.
A single centre study, conducted in India, however, comparing a partogram with a latent phase (composite) and one without, demonstrated more favourable outcomes for the mother and baby when the modified chart was used. It is possible that partograms may be useful in settings with poorer access to healthcare resources, as studies in Mexico and Africa also showed some reduction in caesarean section rates with partogram use and early intervention for delayed progress in labour.
Four pairs of hospitals in south east Asia were invited to participate (2 pairs in Indonesia, 1 each in Thailand and Malaysia).
All the centres functioned as district general hospitals in urban environments with adequate medical and midwifery staffing and suitable facilities for operative obstetric care.
All were already practising active labour management including oxytocin augmentation.
The study ran for 15 months from 1 January, 1990.
During the first Five months, all centres collected data on their deliveries on a standardised form for entry onto the database held on computer at WHO headquarters in Geneva.
After Five months, the WHO partograph was randomly introduced in one of each hospital pair.
Ten months into the study, the partograph was introduced into the remaining hospitals and thus used in all 8 for the last 5months. No discussions were held concerning labour management or